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G Kimber

Publications and source records attributed to G Kimber.

12 recordsLinked to original sources
PubMed1992

Developments in the meiotic analysis of hybrids. I. Review of theory and optimization in triploids.

The theory, construction and optimization of a model of chromosome pairing in triploid hybrids are re-examined and the model reconstructed. A new approach to optimization is described that removes a bias in the estimation of x, the measure of relative affinity, by weighting the observed and calculated meiotic figure frequencies by the number of chromosomes in each figure type. The amended analysis is compared with its antecedent and with other models.

Hybridization, Genetic↗
PubMed1992

Developments in the meiotic analysis of hybrids. II. Amended models for tetraploids.

Amended models of meiotic behaviour in tetraploid species' hybrids have been constructed which better reflect the theory and assumptions about chromosome pairing necessary to conduct such analyses. In particular they correct problems concerning the distribution of chiasmata among and within chromosome configurations inherent in the earlier models of Kimber & Alonso (1981). In general these analyses give similar interpretations to the earlier models but in some cases call the previous conclusions into question.

Hybridization, Genetic↗
PubMed1990

Genomic analysis of diploid plants.

The numerical analysis of meiosis in the triploid hybrid between an induced autotetraploid and a related diploid provides the basis for investigations of the genomic relationships of diploid species based on chromosome pairing. It is also possible to make legitimate comparisons between different triploid hybrids of this type so that the genomic relationships can be converted into measures of phylogenetic distance for taxa where only diploids are known.

Journal Article↗
PubMed1988

Analysis of pivotal-differential evolutionary patterns.

The numerical analysis of meiosis in hybrids between a wild allotetraploid and an autotetraploid of one of its putative diploid progenitors allows the identification of which genomes are pairing and also the verification of pivotal-differential evolution. This type of analysis should be applicable to all genera in which allopolyploid series exist.

Journal Article↗
PubMed1984

The theory of the pairing of telocentric chromosomes in triploids and trisomics.

The possible pairing patterns of telocentric chromosomes in triploids and trisomics are considered and expressions are derived allowing the prediction of expected meiotic, chromosomal, and cellular pairing patterns. The calculation of the relative affinity of the homoeologous chromosomes involved in the pairing patterns with the telocentrics is discussed.

Chromosomes↗
PubMed1979

Uses of wheat aneuploids.

There is available in wheat a unique series of aneuploids ranging from all 21 possible monosomics to complex types that are simultaneously deficient for one chromosome and duplicate for another. Furthermore, lines with chromosomes from related alien species either added to or substituted for wheat chromosomes are in common cytological use. This contribution condiders the use of this range of material in studies designed to elucidate the evolutionary relationships of the species, in investigations of the genetics of a polyploid with cytological diploidization, and in potential breeding manipulations.

Breeding↗
PubMed1974

Giemsa C-banding and the evolution of wheat.

The somatic chromosomes of common wheat, Triticum aestivum L. (2n = 6x = 42), and those of two of its diploid progenitors and T. speltoides, have been individually identified by a Giemsa staining technique. In wheat, telocentric chromosomes were used to aid the recognition of individual chromosomes, and an ideogram has been constructed depicting the C-band positions. There is no similarity in the C-banding of chromosomes within a homoeologous group, with the possible exception of group 5. Comparisons of the C-banding of the diploid species T. monococcum, T. speltoides, and T. tauschii with that of the A, B, and D genomes, respectively, in hexaploid wheat corroborate that T. speltoides could not be the donor of the B genome to wheat and that T. monococcum and T. tauschii are the probable donors of the A and D genomes, respectively.

Journal Article↗
PubMed1974

The Giemsa C-banded karyotype of rye.

The chromosomes of rye have been individually identified by their distinctive heterochromatin pattern with Giemsa staining and classified on the basis of their homoeology with wheat chromosomes. The constitutive heterochromatin detected by C-banding has been shown to be identical with the classical heterochromatin as seen in the pachytene of meiosis in rye.

Chromosomes↗
PubMed1972

A reassessment of the course of evolution of wheat.

Chromosome pairing in hybrids involving Triticum aestivum and new accessions of T. speltoides, and in an amphiploid of these species, indicates that T. speltoides can no longer be considered to be the donor of the B genome of the polyploid wheats. This necessitates a reconsideration of the genome relationships and evolutionary processes that gave rise to cultivated wheats.

Journal Article↗
PubMedDate not supplied

The use of aneuploids in studies of genetics, breeding, and evolution in wheat.

In wheat a unique series of aneuploids is available, ranging from all 21 possible monosomics to complex types which are simultaneously deficient for one chromosome and duplicate for another. Furthermore, lines with chromosomes from related, alien species either added to or substituted for wheat chromosomes are in common cytological use. This contribution considers the use of this range of material in studies designed to elucidate the evolutionary relationships of the species, investigations of the genetics of a polyploid with cytological diploidization, and in potential breeding manipulations.

Aneuploidy↗
PubMedDate not supplied

Comparison of the metabolic response to a glucose tolerance test and a standardized test meal and the response to serial test meals in normal healthy subjects.

The plasma glucose and insulin response to a standardized meal test breakfast was compared with the time-honored glucose tolerance test in the same normal healthy subjects. The amplitude of glycemic excursion and between-subject variation was less with the more physiologic standardized test meal than with that seen with the glucose tolerance test. The glucose tolerance test's prime function is to amplify any glucose intolerance, thus aiding diagnosis, whereas a standardized meal gives a more clinically relevant metabolic status. The administration of serial test meals during the same day in a smaller group of normal subjects indicated, as seen previously with repeated glucose tolerance tests, a diminishing carbohydrate tolerance during the day.

Adult↗